Human Red Cell Instability and Senescence 229 



seem not unnatural that those parts of the cell which organize 

 the repair are themselves more resistant to the attrition of 

 physical agencies than the components they repair. An 

 interesting and somewhat paradoxical support for this notion 

 comes from the experiments of Gabrio and Finch (1954). 

 They find that the survival of red cells during storage at 4° 

 is inversely related to their specific age. This result would not 

 be unexpected if the repair capacity of the cell declined during 

 its life-span and was compensated by a continuous increase in 

 resistance to diffusion. 



Conclusions 



In accord with the best principles of serendipity this investi- 

 gation has established some unsought facts on the structure 

 and status of the red cell, but the goal, the solution of the 

 problem of its senescence still lies ahead. Nevertheless, two 

 conclusions which appear to be relevant to the general problem 

 of ageing can be drawn from the experimental evidence. 

 The first of these concerns cold storage ; the use of cold storage 

 as a method of suspending viability is now well established in 

 practice and may increase in importance as an experimental 

 technique for research on ageing. For example, the work of 

 Billingham and Medawar (1952), and Billingham (1953) has 

 shown that the reimplantation of cold-stored infant tissue 

 into the same adult animal is technically possible. The experi- 

 mental results suggest that the success of cold storage as a 

 method of suspending viability results from the arrest of 

 diffusion processes and not, as was commonly thought, from 

 the cessation of metabolic activity alone. Should cold storage 

 become established as a technique for the investigation of 

 ageing processes, then the proper understanding of the 

 mechanism of its action is necessary both for its theoretical 

 implications, and for defining the optimum conditions of 

 storage. 



The experimental results also offer confirmation for the 

 notion that the red cell is in fact a steady state system in 



